What is the OS you are using? Linux wise you are spoiled for choices but for Windows it is extremely limited.
I tried ISPconfig, quite good, even the paid ones for eg Directadmin Internal licenses are very cheap and stable. However Cpanel is still by far the most popular, pity it is very expensive compared to Directadmin and cannot be compared to the free ones. Using the free ones does have the advantage of costs but have a much steeper learning curves.
Well Webmin is kinda legendary now, stable and good especially when used with virtualmin. But I find it very unfriendly for the typical user. I would suggest ISPconfig. Kloxo etc, there are tons of free or GPL panels. But I suggest if you are running a hosting company get Directadmin at least, best is of course Cpanel, if you are into hobby, the ones I mentioned earlier on should be more than sufficient.
Kloxo It is a fully scriptable, distributed and a 100% object oriented hosting platform which supports Apache/Lighttpd, djbdns/bind and pure-ftpd. The platform enables the end user to manage every aspect of a web hosting account while providing the admin the ability to manage the whole system. VHCS It is written in PHP, Perl and C. The system provides full control over the server, resellers and end users. The application can communicate with database, email, web and DNS servers, monitor traffic or diskspace used and more. ISPConfig ISPConfig is a multilingual control panel that can manage every hosting related service (web, database, DNS, e-mail, ftp, stats). It supports admin, reseller and end-user user levels with configurable quotas for every service. OpenPanel OpenPanel has a simple and slick GUI for controlling the websites (also, there is ab optional command line interface too). It can manage Apache2, Bind DNS, Postfix and Courier-IMAP e-mails, PureFTPd, AWStats and more. SysCP This is an easy to install and use control panel for LAMP servers which supports many common web, e-mail and FTP server software. It has various 3rd party modules like backup, SpamAssassin and more. GNUPanel GNUPanel is a web hosting automation application which is built with PHP5. Administrators can easily create websites, databases, ftp or e-mail accounts and, optionally, create end-users and provide them the passwords so they anyone can manage their own website. EHCP EHCP is a panel that is built with PHP with features like backup-restore, SSL, script installer and more. It is a multilanguage application and has 4 different user levels: server admin, reseller, domain admin and email user. BlueOnyx BlueOnyx is pretty different considering how it is packaged. It is a Linux distribution (based on CentOS v5.5) which aims at delivering a turnkey server appliance for webhosting. It is built with PHP5-MySQL 5 and has phpMyAdmin + webmail integrated . Webmin & Virtualmin Webmin is one of the most popular open source and free web hosting control panels around. It enables you to control user accounts, Apache, DNS, file sharing, MySQL, e-mail servers and more.
Yes, zpanel is loaded with security issues. If you plan on public hosting cpanel is the defacto go to control panel. It is easily the most common. But that comes at a price, unfortunately. Many of the free control panels either are limited in features, or are have their fair share of security issues. You get what you pay for. At a minimum I would recommend webmin. Other than that I would recommend learning how to run a shared hosting server. Once you figure it out, it's not only gratifying that you did it all on your own, but you also learned how to troubleshoot if an issue came up. And you wouldn't be reliable on a third party control panel.
Just one caution about these control panels. If you ever try to switch panels or modify things outside of the panel, you can often run into problems. Most panels (even paid ones like cPanel/Plesk) have their own way of doing things. So you get locked into that method. If you have just a few sites/services, learning how to get by without a control panel provides better security, performance, portability and reliability. I often consider these factors: Frequency of changes Number of different services (email, web, database, dns) Number of accounts/domains If these numbers are low, then I opt for no control panel.
VestaCP is a really good free one if you are just running your own sites. If you have customers, save yourself a big headache and just purchase a cpanel license.